Everyone who ever had to investigate the reason for slow dashboard charts probably knows about the Report Stats overview page under 'report_stats.list'. It is a good way to check how often a chart was loaded and how much time it took to fetch the data (if that is what the run time indicates). However, I noticed that these run times do not reflect the actual load times of the charts on the productive page at all.

When researching about other methods of how to measure and improve dashboard charts I came across this page which describes how to set a load time threshold and a maximum number of concurrently loading charts: https://docs.servicenow.com/bundle/madrid-performance-analytics-and-reporting/page/use/dashboards/ta...

And I found out that setting the threshold to 1 second (which is the minimal value) will stop the long-running charts from loading and displays an estimation of their loading times instead. This is a nice way to compare the actual load times of all the charts in the dashboard page. The displayed values are pretty accurate and can even be validated by clicking on the 'Load' button for rendering the respective chart.

To summarize:

sys_properties.list > glide.canvas.grid.widget_performance_threshold > value 1